trade with friends and/or wifi trading
type this code 010075DA and now u can get all three starter Pokemon
no you can not
Trade
Trade for them.
you must trade with a freind that has a starter pokemon that you dont have.
Only on Pokemon yellow.
you have to trade them from other Pokemon games
You cannot get all 3 Starter Pokemon in Pokemon Emerald without trading for the other 2.
chose one starter Pokemon and beat your rival on hit with a critical.the professor will congragulate you by giving you all three starters
action replay or trading
Get a Action Replay DS or trading.
One way is to get your first starter Pokemon and trade it with your friend. Start the game over. Do the same process to the to other two starter Pokemon. Then get three more Pokemon to trade with on your fourth time starting over so you can trade back all three Pokemon.